I am following an instructable to build a clock that displays the time in English words using LEDs. The output of the circuit is controlled using 3 8 bit shift registers and 3 transistor arrays. I am currently testing the circuit using a breadboard and LEDs. I have attached the schematic from the instructable and my modification of that schematic to use the 74HC595 registers I had available instead of the HCF4094s used in the instructable as well as the Arduino code being used.
Problem
Whenever the minute indicator should move from "QUARTER" to "TEN" all LEDs turn off and the circuit does not resume functioning unless I unplug it for about a minute and plug it back in.
Troubleshooting so Far
Problem
Whenever the minute indicator should move from "QUARTER" to "TEN" all LEDs turn off and the circuit does not resume functioning unless I unplug it for about a minute and plug it back in.
Troubleshooting so Far
- I have tested the code using an Arduino Nano connected to 3 shift registers with LED outputs with no issue. The clock worked for all times.
- By default, the clock begins at "HALF PAST NINE". Using the hour and minute increment buttons, I can cycle through all hours successfully; however, when attempting to cycle through minutes the device ceases to function when I try to increment from "QUARTER TO [hour]" to "TEN MINUTES TO [hour]". Leaving the clock to change time on its own yields the same result. When it should move past "QUARTER" all LEDs turn off.
- I have checked for voltage across the OE' pins after the LEDs turn off. It is a low signal (.1/.2 V).
- I made and ran a program that clocks the registers and sends a 1 to the Data lead every 8 clock cycles. This lead to the discovery of some wiring issues and fixes, but revealed nothing in regards to the issue above.
Attachments
-
3.6 MB Views: 7
-
334.7 KB Views: 7
-
13 KB Views: 4